Image display device and method for operating the same

ABSTRACT

An image display device and a method for operating the same are disclosed. The method for operating the image display device including a plurality of backlight lamps arranged on upper and lower sides of a rear surface of a display panel includes receiving a 3-Dimensional (3D) image, alternately aligning a left-eye image and a right-eye image of the 3D image, and alternately displaying the aligned left- and right-eye images. In the displaying step, the backlight lamps arranged on the upper side of the panel and the backlight lamps arranged on the lower side of the panel are turned on in a portion of a period of the left-eye image or the right-eye image.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of U.S. ProvisionalApplication No. 61/305,967 filed on Feb. 19, 2010 in the USPTO, thedisclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the invention

The present invention relates to an image display device and a methodfor operating the same, and more particularly to an image displaydevice, which is capable of reducing crosstalk when a 3-Dimensional (3D)image is displayed, and a method for operating the same.

2. Description of the Related Art

An image display device includes a function for displaying a viewableimage to a user. The user can view a broadcast using the image displaydevice. The image display device displays a broadcast, which is selectedby the user from broadcast signals transmitted from a broadcast station,on a display. Currently, analog broadcasting is being phased out infavor of digital broadcasting.

A digital broadcast refers to a broadcast for transmitting digital videoand audio signals. The digital broadcast has low data loss due torobustness against external noise, advantageous error correction,high-resolution screen, as compared with an analog broadcast. Inaddition, the digital broadcast can provide a bidirectional serviceunlike the analog broadcast.

Recently, research into stereoscopic images has been actively conducted.In addition, in various environments and technologies as well as acomputer graphics field, the stereoscopic image technology has becomeincreasingly common and put to practically use.

SUMMARY OF THE INVENTION

Therefore, the present invention has been made in view of the aboveproblems, and it is an object of the present invention to provide animage display device, which is capable of reducing crosstalk when a3-Dimensional (3D) image is displayed, and a method for operating thesame.

It is another object of the present invention to provide an edge typeimage display device including a hold type liquid crystal panel andbacklight lamps arranged on upper and lower sides of the panel, which iscapable of reducing crosstalk, and a method for operating the same.

It is another object of the present invention to provide an imagedisplay device, which is capable of improving luminance when a 3D imageis displayed, and a method for operating the same.

It is another object of the present invention to provide an imagedisplay device, which is capable of reducing instantaneous load whenbacklight lamps are driven, and a method for operating the same.

In accordance with an aspect of the present invention, the above andother objects can be accomplished by the provision of a method foroperating an image display device including a plurality of backlightlamps arranged on upper and lower sides of a rear surface of a displaypanel, the method including: receiving a 3-Dimensional (3D) image,alternately aligning a left-eye image and a right-eye image of the 3Dimage, and alternately displaying the aligned left- and right-eyeimages, wherein, in the displaying step, the backlight lamps arranged onthe upper side of the panel and the backlight lamps arranged on thelower side of the panel are turned on in a portion of a period of theleft-eye image or the right-eye image.

In accordance with another aspect of the present invention, there isprovided a method for operating an image display device including aplurality of backlight lamps arranged on upper and lower sides of a rearsurface of a display panel, the method including: receiving a2-Dimensional (2D) image, displaying the 2D image, receiving a3-Dimensional (3D) image, alternately aligning a left-eye image and aright-eye image of the 3D image, and alternately displaying the alignedleft- and right-eye images, wherein the level of current flowing in thelamps per unit frame when the 3D image is displayed is greater than thatwhen the 2D image is displayed.

In accordance with another aspect of the present invention, there isprovided an image display device including: a formatter configured toalternately align a left-eye image and a right-eye image of a3-Dimensional (3D) image, and a display configured to alternatelydisplay the aligned left- and right-eye images, wherein the displayincludes a plurality of backlight lamps arranged on upper and lowersides of a rear surface of a display panel, and wherein the backlightlamps arranged on the upper side of the panel and the backlight lampsarranged on the lower side of the panel are turned on in a portion of aperiod of the left-eye image or the right-eye image.

According to the embodiments of the present invention, in order toalternately align and display the left-eye image and the right-eye imageof the 3D image, the backlight lamps arranged on the upper and lowersides of the panel are turned on in the portion of the period of thealigned left- and right-eye image, thereby preventing crosstalk in whichadjacent images are displayed when the 3D image is displayed.

By setting the level of current flowing in the backlight lamps when the3D image is displayed to be greater than that when the 2D image isdisplayed, it is possible to improve luminance when the 3D image isdisplayed.

By turning the backlight lamps arranged on the upper side of the paneland the backlight lamps arranged on the lower side of the panel on to bedriven at different times by scanning drive, it is possible to reduceinstantaneous load when the backlight lamps are driven and, as a result,to reduce power consumption when the lamps are driven.

By increasing the frame rate of the 3D image and consecutively arrangingthe same left-eye image frames and the same right-eye image frames, itis possible to prevent crosstalk in which adjacent images are displayedwhen the 3D image is displayed.

In particular, in a state in which the same left-eye image frames andthe same right-eye image frames are consecutively arranged, thebacklight lamps arranged on the upper side of the panel and thebacklight lamps arranged on the lower side of the panel are turned on,in at least a last left-eye image frame of the consecutive left-eyeimage frames or at least a last right-eye image frame of the consecutiveright-eye image frames. Accordingly, it is possible to prevent crosstalkin which adjacent images are displayed when the 3D image is displayed.

In addition, in a state in which the same left-eye image frames and thesame right-eye image frames are consecutively arranged, using a boundarybetween the consecutive left-eye image frames or a boundary between theconsecutive right-eye image frames as a reference, any backlight lampsof the backlight lamps arranged on the upper side of the panel and thebacklight lamps arranged on the lower side of the panel are turned onbefore the boundary and the other backlight lamps are turned on afterthe boundary. Accordingly, it is possible to prevent crosstalk in whichadjacent images are displayed when the 3D image is displayed.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and other advantages of thepresent invention will be more clearly understood from the followingdetailed description taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 a block diagram showing an image display device according to anembodiment of the present invention;

FIG. 2 is a block diagram showing an example of a power supply unit anda display of FIG. 1;

FIG. 3 is a diagram showing arrangement of backlight lamps of FIG. 2;

FIG. 4 is a block diagram showing a controller of FIG. 1;

FIG. 5 is a diagram showing various formats of a 3D image;

FIG. 6 is a diagram showing an operation of shutter glasses according toa frame sequential format of FIG. 5;

FIG. 7 is a diagram illustrating a state in which an image is formed bya left-eye image and a right-eye image;

FIG. 8 is a diagram illustrating the depth of a 3D image according to adistance between a left-eye image and a right-eye image;

FIG. 9 is a flowchart illustrating a method for operating an imagedisplay device according to an embodiment of the present invention; and

FIGS. 10 to 20 are diagrams illustrating various examples of the methodfor operating the image display device of FIG. 9.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Exemplary embodiments of the present invention will be described withreference to the attached drawings.

The terms “module” and “unit” as used to describe components herein areused to help the understanding of the components and thus they shouldnot be considered as having specific meanings or roles. Accordingly, theterms “module” and “unit” may be used interchangeably.

FIG. 1 a block diagram showing an image display device according to anembodiment of the present invention.

Referring to FIG. 1, the image display device 100 according to theembodiment of the present invention includes a tuner 110, a demodulator120, an external device interface unit 130, a network interface unit135, a memory 140, a user input interface unit 150, a controller 170, adisplay 180, an audio output unit 185, a power supply unit 190, and a 3Dsupplementary display 195.

The tuner 110 tunes to a Radio Frequency (RF) broadcast signalcorresponding to a channel selected by a user from RF broadcast signalsreceived through an antenna or each of all channels stored in advance.The tuned RF broadcast signal is converted into an IntermediateFrequency (IF) signal or a baseband video or audio signal.

For example, if the tuned RF broadcast signal is a digital broadcastsignal, the tuned RF broadcast signal is converted into a digital IF(DIF) signal and, if the tuned RF broadcast signal is an analogbroadcast signal, the tuned RF broadcast signal is converted into ananalog baseband video/audio signal (Composite Video Baseband Signal(CVBS)/Sound IF (SIF)). That is, the tuner 110 may process a digitalbroadcast signal or an analog broadcast signal. The analog basebandvideo/audio signal (CVBS/SIF) output from the tuner 110 may be directlyinput to the controller 170.

In addition, the tuner 110 may receive an RF broadcast signal of asingle carrier according to an Advanced Television System Committee(ATSC) system or an RF broadcast signal of multiple carriers accordingto a Digital Video Broadcasting (DVB) system.

The tuner 110 may sequentially tune to the RF broadcast signals of allthe broadcast channels stored through a channel storage function amongthe RF broadcast signals received through the antenna, and convert thesignals into IF signals or baseband video or audio signals, in thepresent invention.

The demodulator 120 receives the DIF signal converted by the tuner 110and performs a demodulation operation.

For example, if the DIF signal output from the tuner 110 is based on theATSC system, the demodulator 120 performs 8-Vestigal Side Band (VSB)modulation. In addition, the demodulator 120 may perform channeldecoding. The demodulator 120 may include a trellis decoder, adeinterleaver, a Reed-Solomon decoder and the like and perform trellisdecoding, deinterleaving and Reed-Solomon decoding.

For example, if the DIF signal output from the tuner 110 is based on theDVB system, the demodulator 120 performs Coded Orthogonal FrequencyDivision Multiple Access (COFDMA) modulation. In addition, thedemodulator 120 may perform channel decoding. The demodulator 120 mayinclude a convolutional decoder, a deinterleaver, a Reed-Solomon decoderand the like and perform convolutional decoding, deinterleaving andReed-Solomon decoding.

The demodulator 120 may perform demodulation and channel decoding andoutput a Transport Stream (TS) signal. The TS signal may be a signal inwhich an image signal, an audio signal and a data signal aremultiplexed. For example, the TS signal may be an MPEG-2 TS in which anMPEG-2 standard image signal, a Dolby AC-3 standard audio signal and thelike are multiplexed. In detail, the MPEG-2 TS may include a 4-byteheader and a 184-byte payload.

The demodulator 120 may separately include demodulators according to theATSC system and the DVB system. That is, an ATSC modulator and a DVBdemodulator may be included.

The TS signal output from the demodulator 120 may be input to thecontroller 170. The controller 170 performs demultiplexing, image/audiosignal processing and the like, outputs an image through the display 180and audio through the audio output unit 185.

The external device interface unit 130 may connect an external device tothe image display device 100. The external device interface unit 130 mayinclude an A/V input/output unit (not shown) or a wireless communicationunit (not shown).

The external device interface unit 130 may be connected to the externaldevice such as a Digital Versatile Disk (DVD) player, a Blu-ray player,a game console, a camcorder or a computer (notebook type computer) in awired/wireless manner. The external device interface unit 130 sends animage signal, an audio signal or a data signal received from theconnected external device to the controller 170 of the image displaydevice 100. The image signal, the audio signal or the data signalprocessed by the controller 170 may be output to the connected externaldevice. The external device interface unit 130 may include an A/Vinput/output unit (not shown) or a wireless communication unit (notshown).

The A/V input/output unit inputs the image signal and the audio signalof the external device to the image display device 100 and may include aUniversal Serial Bus (USB) port, a CVBS terminal, a component terminal,an S-video terminal (analog), a Digital Visual Interface (DVI) terminal,a High Definition Multimedia Interface (HDMI) terminal, an RGB terminal,and a D-SUB terminal.

The wireless communication unit may perform wireless Local Area Network(LAN) communication with another electronic device. The image displaydevice 100 may be connected to another electronic device over a networkaccording to the communication standard such as Bluetooth, RadioFrequency Identification (RFID), Infrared Data Association (IrDA), UltraWideband (UWB), or ZigBee.

In addition, the external device interface unit 130 may be connected tovarious set-top boxes through at least one of the above-describedvarious terminals so as to perform an input/output operation with theset-top boxes.

The external device interface unit 130 may transmit or receive data toor from the 3D supplementary display 195.

The network interface unit 135 provides an interface for connecting theimage display device 100 to a wired/wireless network including anInternet network. The network interface unit 135 may include an Ethernetport, for connection with a wired network. For connection with awireless network, the communication standard such as Wireless LAN (WLAN)(Wi-Fi), Wireless broadband (Wibro), World Interoperability forMicrowave Access (Wimax), or High Speed Downlink Packet Access (HSDPA)may be used.

The network interface unit 135 may receive content or data provided byan Internet or content provider or a network manager over a network.That is, the network interface unit 135 may receive content such asmovies, advertisements, games, VODs, or broadcast signals andinformation associated therewith provided by the content provider over anetwork. In addition, the network interface unit 135 may receive updateinformation, and update file of firmware provided by the networkmanager. In addition, the network interface unit 135 may transmit datato the Internet or content provider or the network manager.

In addition, the network interface unit 135 is connected to, forexample, an Internet Protocol TV (IPTV) so as to receive and transmit animage, audio or data signal processed by a set-top box for IPTV to thecontroller 170 and to transmit signals processed by the controller 170to the set-top box for IPTV, in order to perform bidirectionalcommunication.

The IPTV may include ADSL-TV, VDSL-TV, FFTH-TV or the like according tothe type of transmission network or include TV over DSL, Video over DSL,TV over IP (TVIP), Broadband TV (BTV), or the like. In addition, theIPTV may include an Internet TV capable of Internet access or afull-browsing TV.

The memory 140 may store a program for performing signal processing andcontrol in the controller 170 and store a processed image, audio or datasignal.

In addition, the memory 140 may perform a function for temporarilystoring an image, audio or data signal input through the external deviceinterface unit 130. In addition, the memory 140 may store informationabout predetermined broadcast channels through a channel storagefunction such as a channel map.

The memory 140 may include at least one of a flash memory type storagemedium, a hard disk type storage medium, a multimedia card micro typemedium, a card type memory (e.g., SD memory, XD memory, or the like), aRAM, or a ROM (EEPROM or the like). The image display device 100 mayreproduce and provide a file (a moving image file, a still image file, amusic file, a document file, or the like) stored in the memory 140 tothe user.

Although FIG. 1 shows an embodiment in which the memory 140 is includedseparately from the controller 170, the present invention is not limitedthereto. The memory 140 may be included in the controller 170.

The user input interface unit 150 sends a signal input by the user tothe controller 170 or sends a signal from the controller to the user.

For example, the user input interface unit 150 may receive a user inputsignal, such as power on/off, channel selection or screen setup, from aremote control device 200 or transmit a signal from the controller 170to the remote control device 200, according to various communicationsystems such as a Radio Frequency (RF) communication system or anInfrared (IR) communication system.

In addition, for example, the user input interface unit 150 may send auser input signal input through a local key (not shown) such as a powerkey, a channel key, a volume key, or a setup value to the controller170.

In addition, for example, the user input interface unit 150 may send auser input signal received from a sensing unit (not shown) for sensingthe gesture of the user to the controller 170 or transmit a signal fromthe controller 170 to the sensing unit (not shown). The sensing unit(not shown) may include a touch sensor, a voice sensor, a positionsensor, a motion sensor, or the like.

The controller 170 may demultiplex the TS signal input through the tuner110, the demodulator 120 or the external device interface unit 130 orprocess the demultiplexed signals, and generate and output signals foran image or audio output.

The image Signal processed by the controller 170 may be input to thedisplay 180 such that an image corresponding to the image signal isdisplayed. The image signal processed by the controller 170 may be inputto an external output device through the external device interface unit130.

The audio signal processed by the controller 170 may be audibly outputthrough the audio output unit 185. In addition, the audio signalprocessed by the controller 170 may be input to an external outputdevice through the external device interface unit 130.

Although not shown in FIG. 1, the controller 170 may include ademultiplexer, an image processing unit, and the like. These will bedescribed in detail with reference to FIG. 4.

The controller 170 may control the overall operation of the imagedisplay device 100. For example, the controller 170 may control thetuner 110 so as to tune to an RF broadcast corresponding to a channelselected by the user or a channel stored in advance.

In addition, the controller 170 may control the image display device 100according to a user command input through the user input interface unit150 or an internal program.

For example, the controller 170 controls the tuner 110 such that thesignal of a channel selected according to a predetermined channelselection command received through the user input interface unit 150 isinput. The image, audio or data signal of the selected channel isprocessed. The controller 170 may control information about the channelselected by the user to be output through the display 180 or the audiooutput unit 185 together with the image or audio signal.

As another example, the controller 170 may control an image or audiosignal received from an external device, for example, a camera or acamcorder, through the external device interface unit 130 to be outputthrough the display 180 or the audio output unit 185, according to anexternal device image reproduction command received through the userinput interface unit 150.

The controller 170 may control the display 180 to display an image. Forexample, the controller may control a broadcast image input through thetuner 110, an external input image input through the external deviceinterface unit 130, an image input through a network interface unit 135,or an image stored in the memory 140 to be displayed on the display 180.

At this time, the image displayed on the display 180 may be a stillimage, a moving image, a 2D image or a 3D image.

The controller 170 generates and displays a predetermined object in theimage displayed on the display 180 as a 3D object. For example, theobject may be at least one of a connected web screen (newspaper,magazine, or the like), an Electronic Program Guide (EPG), variousmenus, a widget, an icon, a still image, a moving image, or a text.

Such a 3D object may have a sense of depth different from that of theimage displayed on the display 180. Preferably, the 3D object may beprocessed such that the 3D object appears to be located in front of theimage displayed on the display 180.

The controller 170 recognizes a user's position based on an imagephotographed using a photographing unit (not shown). The controller canobtain, for example, a distance (z-axis coordinate) between the user andthe image display device 100. In addition, the controller can obtain anX-axis coordinate and a y-axis coordinate in the image display devicecorresponding to the user's position.

Although not shown in the drawing, a channel browsing processing unitfor generating a thumbnail image corresponding to a channel signal or anexternal input signal may be further included. The channel browsingprocessing unit may receive a Transport Stream (TS) signal output fromthe demodulator 120 or a TS signal output from the external deviceinterface unit 130, extract an image from the received TS signal, andgenerate a thumbnail image. The generated thumbnail image may be inputto the controller 170 without conversion or in a state of being coded.In addition, the generated thumbnail image may be input to thecontroller 170 in a state of being coded into a stream format. Thecontroller 170 may display a thumbnail list including a plurality ofthumbnail images on the display 180 using the received thumbnail images.The thumbnail list may be displayed in a brief viewing manner in whichthe thumbnail list is displayed in a portion of the display 180 in astate in which in a predetermined image is displayed, or in a fullviewing manner in which the thumbnail list is displayed over theentirety of the display 180.

The display 180 converts an image signal, a data signal, an OSD signalor a control signal processed by the controller 170 or an image signal,data signal or a control signal received through the external deviceinterface unit 130 and generates a driving signal.

The display 180 may include a Plasma Display Panel (PDP), a LiquidCrystal Display (LCD), an Organic Light Emitting Diode (OLED) display,and a flexible display. In particular, in the embodiment of the presentinvention, a 3D display is preferable.

For 3D image viewing, the display 180 may be divided into asupplementary display type and a single display type.

In the single display type, a 3D image is implemented on the display 180without a separate subsidiary device, e.g., glasses. Examples of thesingle display type may include various types such as a lenticular typeand a parallax barrier type.

In the supplementary display type, a 3D image is implemented using asubsidiary device, in addition to the display 180. Examples of thesupplementary display type include various types such as a Head-MountedDisplay (HMD) type and a glasses type. The glasses type may be dividedinto a passive type such as a polarized glasses type and an active typesuch as a shutter glasses type. The HMD type may be divided into apassive type and an active type.

In the embodiment of the present invention, for 3D image viewing, the 3Dsupplementary display 195 is included. It is assumed that the 3Dsupplementary display 195 is an active type supplementary display.Hereinafter, the case of using the shutter glasses will be described.

The display 180 may include a touch screen and function as an inputdevice as well as an output device.

The audio output unit 185 receives the audio signal processed by thecontroller 170, for example, a stereo signal, a 3.1 channel signal or a5.1 channel signal, and outputs audio. The audio output unit 185 may beimplemented by various types of speakers.

In order to sense the gesture of the user, as described above, thesensing unit (not shown) including at least one of touch sensor, a voicesensor, a position sensor, a motion sensor, or the like may be furtherincluded in the image display device 100. The signal sensed by thesensing unit (not shown) is sent to the controller 170 through the userinput interface unit 150.

The controller 170 may sense the gesture of the user by the imagephotographed using the photographing unit (not shown), the signal sensedusing the sensing unit (not shown) or a combination thereof.

The power supply unit 190 supplies power to the image display device100. In particular, the power supply unit may supply power to thecontroller 170 implemented in the form of a System On Chip (SOC), thedisplay 180 for displaying an image, and the audio output unit 185 foroutputting audio.

The remote control device 100 transmits a user input signal to the userinput interface unit 150. The remote control device 200 may useBluetooth, Radio Frequency Identification (RFID) communication, IRcommunication, Ultra Wideband (UWB), or ZigBee. The remote controldevice 200 may receive the image, audio or data signal output from theuser input interface unit 150 and display or audibly output the signal.

The image display device 100 may be a fixed digital broadcast receivercapable of receiving at least one of an ATSC (8-VSB) digital broadcast,a DVB-T (COFDM) digital broadcast or an ISDB-T (BST-OFDM) digitalbroadcast, or a mobile digital broadcast receiver capable of receivingat least one of a terrestrial DMB digital broadcast, a satellite DMBdigital broadcast, an ATSC-M/H digital broadcast, a DVB-H (COFDM)digital broadcast or a Media Forward Link Only digital broadcast. Inaddition, the image display device 100 may be a cable, satellite or IPTVdigital broadcast receiver.

The image display device described in the present specification mayinclude a TV receiver, a mobile phone, a smart phone, a notebookcomputer, a digital broadcast terminal, a Personal Digital Assistants(PDA), a Portable Multimedia Player (PMP), or the like.

FIG. 1 is a block diagram of the image display device 100 according toone embodiment of the present invention. The components of the blockdiagram may be combined, added or omitted according to the type of theimage display device 100. That is, two or more components may becombined into one component or one component may be divided into two ormore components, as necessary. The functions of the blocks are intendedto describe, and is not intended to limit the scope of the presentinvention.

Hereinafter, it is assumed that the image display device 100 accordingto the embodiment of the present invention includes an LCD display whichimplements a 3D display and requires a separate backlight unit.

FIG. 2 is a block diagram showing an example of the power supply unitand the display of FIG. 1.

Referring to FIG. 2, the LCD display 180 includes a liquid crystal panel210, a driving unit 230 and a backlight unit 250.

The liquid crystal panel 210 includes a first substrate on which aplurality of gate lines GL and data lines DL are arranged in a matrix soas to intersect each other and thin film transistors and pixelelectrodes connected thereto are formed at intersections of the lines, asecond substrate including a common electrode, and a liquid crystallayer formed between the first substrate and the second substrate, inorder to display an image.

The driving unit 230 drives the liquid crystal panel 210 using a controlsignal and a data signal supplied from the controller 170 of FIG. 1. Thedriving unit 230 includes a timing controller 232, a gate driver 234 anda data driver 236.

The timing controller 232 receives a control signal, RGB data signals, avertical synchronization signal Vsync and the like from the controller170, controls the gate driver 234 and the data driver 236 according tothe control signal, rearranges RGB data signals, and supplies the RGBdata signals to the data driver 236.

A scanning signal and an image signal are supplied to the liquid crystalpanel 210 through the gate lines GL and the data lines DL, under thecontrol of the gate driver 234, the data driver 236 and the timingcontroller 232.

The backlight unit 250 supplies light to the liquid crystal panel 210.The backlight unit 250 may include a plurality of backlight lamps 252functioning as a light source, a scanning driving unit 254 forcontrolling scanning drive of the backlight lamps 252, and a lampdriving unit 256 for turning the backlight lamps 252 on/off.

A predetermined image is displayed using the light emitted from thebacklight unit 250, in a state in which light transmission of the liquidcrystal layer is adjusted by an electric field formed between the pixelelectrodes and the common electrode of the liquid crystal panel 210.

The power supply unit 190 may supply a common electrode voltage Vcom tothe liquid crystal panel 210 and supply a gamma voltage to the datadriver 236. In addition, the power supply unit 190 supplies drivingpower to drive the backlight lamps 252.

FIG. 3 is a diagram showing the arrangement of backlight lamps of FIG.2.

First, referring to the drawing, the image display device 100 accordingto the embodiment of the present invention may include the display 180including the liquid crystal panel 210 and the plurality of backlightlamps 252-1, 252-2, . . . , and 252-4. The plurality of backlight lamps252-1, 252-2, . . . , and 252-4 may be Light Emitting Diode (LED) typebacklight lamps.

The plurality of backlight lamps 252-1, 252-2, . . . , and 252-4 may bearranged on the rear surface of the liquid crystal panel 210 and, moreparticularly, on upper and lower sides of the liquid crystal panel 210.If the plurality of backlight lamps 252-1, 252-2, . . . , and 252-4 areturned on, the light is irradiated onto the entire surface of the liquidcrystal panel 210 by a diffusion plate for diffusing the light from thelamps, a reflection plate for reflecting light, an optical sheet forpolarizing, emitting or diffusing light, or the like. This displaydevice is called en edge type display device.

The backlight lamps 252-1 and 252-2 arranged on the upper side of theliquid crystal panel 210 and the backlight lamps 252-3 and 252-4arranged on the lower side of the liquid crystal panel 210 may besequentially turned on at different times or may be turned on so as toat least partially overlap each other.

Alternatively, the backlight lamps may be arranged on any one of theupper and lower sides of the liquid crystal panel 210, the number ofbacklight laps arranged on the upper side and the lower side of theliquid crystal panel 210 may be changed, and the backlight lampsarranged on the upper side and the lower side of the liquid crystalpanel may have a linear shape.

FIG. 4 is a block diagram showing the controller of FIG. 1, FIG. 5 is adiagram showing various formats of a 3D image, and FIG. 6 is a diagramshowing an operation of shutter glasses according to a frame sequentialformat of FIG. 5.

Referring to the drawings, the controller 170 according to oneembodiment of the present invention may include a demultiplexer 410, animage processing unit 420, an OSD generator 440, a mixer 445, a FrameRate Converter (FRC) 450, and a formatter 460. In addition, an audioprocessing unit (not shown) and a data processing unit (not shown) maybe further included.

The demultiplexer 410 demultiplexes an input TS signal. For example, ifan MPEG-2 TS signal is input, the demultiplexer may demultiplex andseparate the MPEG-2 TS signal into image, audio and data signals. The TSsignal input to the demultiplexer 410 may be a TS signal output from thetuner 110, the demodulator 120 or the external device interface unit130.

The image processing unit 420 may process the demultiplexed imagesignal. The image processing unit 420 may include an image decoder 425and a scaler 435.

The image decoder 425 decodes the demultiplexed image signal and thescaler 435 adjusts the resolution of the decoded image signal such thatthe image signal can be output through the display 180.

The image decoder 425 may include various types of decoders.

For example, if the demultiplexed image signal is a 2D image signalencoded based on the MPEG-2 standard, the image signal may be decoded byan MPEG-2 decoder.

In addition, for example, if the demultiplexed 2D image signal is animage signal encoded based on the H.264 standard according to a DigitalMultimedia Broadcasting (DMB) or DVB-H system, a depth image signal ofMPEG-C part 3, a multi-view image signal according to Multi-view VideoCoding (MVC) or a free-viewpoint image signal according toFree-viewpoint TV (FTV), the image signal may be decoded by a H.264decoder, an MPEG-C decoder, an MVC decoder or an FTV decoder.

The image signal decoded by the image processing unit 420 may include a2D image signal, a mixture of a 2D image signal and a 3D image signal, a3D image signal.

The image processing unit 420 may detect whether the demultiplexed imagesignal is a 2D image signal or a 3D image signal. The 3D image signalmay be detected based on a broadcast signal received from the tuner 110,an external input signal from an external device, or an external inputsignal received over a network. In particular, the 3D image signal maybe detected by referring to a 3D image flag in a stream headerindicating 3D image, 3D image metadata, or format information of 3Dimage.

The image signal decoded by the image processing unit 420 may include 3Dimage signals in various formats. For example, the decoded image signalmay be a 3D image signal including a color difference image and a depthimage, or a 3D image signal including multi-view image signals. Themulti-view image signals may include, for example, a left-eye imagesignal and a right-eye image signal.

As shown in FIG. 5, the format of the 3D image signal may include aside-by-side format (FIG. 5( a)) in which the left-eye image L and theright-eye image R are arranged in a horizontal direction, a top/downformat in which the left-eye image and the right-eye image are arrangedin a vertical direction, frame sequential format (FIG. 5( c)) in whichthe left-eye image and the right-eye image are time-divisionallyarranged, an interlaced format (FIG. 5( d)) in which the left-eye imageand the right-eye image are mixed in line units, and a checker boxformat (FIG. 5( e)) in which the left-eye image and the right-eye imageare mixed in box units.

The OSD generator 440 generates an OSD signal according to a user inputsignal or automatically. For example, based on a user input signal, asignal for displaying a variety of information on the screen of thedisplay 180 using graphics or text may be generated. The generated OSDsignal may include a variety of data such as a user interface screen,various menu screens, a widget or an icon of the image display device100. The generated OSD signal may include a 2D object or a 3D object.

The mixer 445 may mix the OSD signal generated by the OSD generator 440with the image signal decoded by the image processing unit 420. At thistime, the OSD signal and the decoded image signal may include at leastone of a 2D signal and a 3D signal. The mixed image signal is providedto the FRC 450.

The FRC 450 converts the frame rate of the input image. For example, aframe rate of 60 Hz is converted into 120 Hz or 240 Hz or 480 Hz. If theframe rate of 60 Hz is converted into 120 Hz, a first frame may beinserted between the first frame and a second frame or a third frameestimated from the first frame and the second frame may be insertedbetween the first frame and the second frame. If the frame rate of 60 Hzis converted into 240 Hz, the same three frames may be inserted or threeestimated frames may be inserted.

The formatter 460 may receive the signal mixed by the mixer 445, thatis, the OSD signal and the decoded image signal, and separate a 2D imagesignal and a 3D image signal.

In the present specification, the 3D image signal includes a 3D object.Examples of such an object may include a Picture In Picture (PIP) image(still image or moving image), an EPG indicating broadcast programinformation, various menus, a widget, an icon, a text, an object, aperson or a background in an image, or a web screen (newspaper,magazine, or the like).

The formatter 460 may change the format of the 3D image signal to, forexample, any one of various formats shown in FIG. 5. In particular, inthe embodiment of the present invention, it is assumed that the formatis changed to the frame sequential format among the formats shown inFIG. 5. That is, the left-eye image signal L and the right-eye imagesignal R are sequentially and alternately aligned. The 3D supplementarydisplay 195 of FIG. 1 preferably uses shutter glasses.

FIG. 6 shows an operation relationship between the shutter glasses 195and the frame sequential format. FIG. 6( a) shows the case where theleft-eye glass of the shutter glasses 195 is opened and the right-eyeglass of the shutter glasses is closed when the left-eye image L isdisplayed on the display 180 and FIG. 6( b) shows the case where theleft-eye glass of the shutter glasses 195 is closed and the right-eyeglass of the shutter glasses is opened.

The formatter 460 may switch a 2D image signal to a 3D image signal. Forexample, according to a 3D image generation algorithm, an edge or aselectable object may be detected from a 2D image signal, and an objectaccording to the detected edge or the selectable object may be separatedto generate a 3D image signal. The generated 3D image signal may beseparated into a left-eye image signal L and a right-eye image signal R,as described above.

The audio processing unit (not shown) in the controller 170 may processthe demultiplexed audio signal. The audio processing unit (not shown)may include various decoders.

For example, if the demultiplexed audio signal is a coded audio signal,the coded audio signal may be decoded. In detail, if the demultiplexedaudio signal is an audio signal coded based on the MPEG-2 standard, theaudio signal may be decoded by an MPEG-2 decoder. If the demultiplexedaudio signal is an audio signal coded based on the MPEG 4 Bit SlicedArithmetic Coding (BSAC) standard according to a terrestrial DMB system,the audio signal may be decoded by an MPEG 4 decoder. If thedemultiplexed audio signal is an audio signal coded based on the MPEG-2Advanced Audio Codec (AAC) standard according to the satellite DMB orDVB-H system, the audio signal may be decoded by an AAC decoder. If thedemultiplexed audio signal is an audio signal coded based on the DolbyAC-3 standard, the audio signal may be decoded by an AC-3 decoder.

The audio processing unit (not shown) in the controller 170 may processbase, treble, volume adjustment or the like.

The data processing unit (not shown) in the controller 170 may processthe demultiplexed data signal. For example, if the demultiplexed datasignal is coded data signal, the coded data signal may be decoded. Thecoded data signal may be EPG information including broadcast informationsuch as a start time and an end time of a broadcast program broadcastedon each channel. For example, the EPG information may includeATSC-Program and System Information Protocol (ATSC-PSIP) information inthe ATSC system and include DVB-Service Information (DVB-SI) in the DVBsystem. The ATSC-PSIP information and the DVB-SI may be included in theabove-described TS, that is, the header (4 bytes) of the MPEG-2 TS.

Although, in FIG. 4, the signals from the OSD generator 440 and theimage processing unit 420 are mixed by the mixer 445 and are subjectedto 3D processing by the formatter 460, the present invention is notlimited thereto and the mixer may be located at a next stage of theformatter. That is, the formatter 460 may perform 3D processing withrespect to the output of the image processing unit 420, the OSDgenerator 440 may generate an OSD signal and performs 3D processing withrespect to the OSD signal, and the mixer 445 may mix the processed 3Dsignals.

FIG. 4 is the block diagram of the controller 170 according to theembodiment of the present invention. The components of the block diagrammay be combined, added or omitted according to the types of thecontroller 170.

In particular, the FRC 450 and the formatter 460 may not be included inthe controller 170 and may be included separately from the controller.

FIG. 7 is a diagram illustrating a state in which an image is formed bya left-eye image and a right-eye image, and FIG. 8 is a diagramillustrating the depth of a 3D image according to a distance between aleft-eye image and a right-eye image.

First, a plurality of images or a plurality of objects 715, 725, 735 and745 is shown in FIG. 7.

First, the first object 715 includes a first left-eye image 711 (L)based on a first left-eye image signal and a first right-eye image 713(R) based on a first right-eye image signal. A distance between thefirst right-eye image 713 and the first left-eye image 711 on thedisplay 180 is set to d1. At this time, the user sees an image thatappears to be formed at an intersection of a line connecting the lefteye 701 and the first left-eye image 711 and a line connecting the righteye 703 and the first right-eye image 713. Accordingly, the user seesthe first object 715 that appears to be located in back of the displayunit 180.

Next, the second object 725 includes a second left-eye image 721 (L) anda second right-eye image 723 (R). Since the second left-eye image 721and the second right-eye image 723 are displayed so as to overlap eachother on the display unit 180, a distance therebetween is set to 0.Accordingly, the user sees the second object 725 that appears to belocated on the display 180.

Next, the third object 735 includes a third left-eye image 731 (L) and athird right-eye image 733 (R), and the fourth object 745 includes afourth left-eye image 741 (L) and a fourth right-eye image 743 (R). Thedistance between the third left-eye image 731 and the third right-eyeimage 733 is set to d3, and the distance between the fourth left-eyeimage 741 and the fourth right-eye image 743 is set to d4.

According to the above-described method, the user sees the third objects735 and the fourth object 745 that appear to be located at positionswhere images are formed, sees the third objects 735 and the fourthobject 745 that appear to be located in front of the display 180, in thedrawing.

At this time, the user sees the fourth object 745 that appears to belocated in front of, that is, protruded from the third object 735. Thedistance d4 between the fourth left-eye image 741 (L) and the fourthright-eye image 743 (R) is greater than the distance d3 between thethird left-eye image 731 (L) and the third right-eye image 733 (R).

In the embodiment of the present invention, the distance between thedisplay 180 and each of the objects 715, 725, 735 and 745, which isrecognized by the user, is expressed by a depth. The depth of the objectthat appears to the user to be located in back of the display 180 has anegative value (−) and the depth of the object that appears to the userto be located in front of the display 180 has a positive value (+). Thatis, the depth value is gradually increased as a degree of protrusion ofthe object from the display toward the user is increased.

Referring to FIG. 8, it can be seen that, if a distance a between aleft-eye image 801 and a right-eye image 802 shown in FIG. 8( a)) isless than a distance b between a left-eye image 801 and a right-eyeimage 802 shown in FIG. 8( b), the depth a′ of the 3D object of FIG. 8(a) is less than the depth b′ of the 3D object of FIG. 8( b).

If the 3D image includes the left-eye image and the right-eye image, aposition of an image that appears to the user to be formed is changedaccording to the distance between the left-eye image and the right-eyeimage. Accordingly, by adjusting the display distance between theleft-eye image and the right-eye image, it is possible to adjust thedepth of the 3D image or the 3D object including the left-eye image andthe right-eye image.

FIG. 9 is a flowchart illustrating a method for operating an imagedisplay device according to an embodiment of the present invention, andFIGS. 10 to 20 are diagrams illustrating various examples of the methodfor operating the image display device of FIG. 9.

Referring to FIG. 9, first, a determination as to whether or not a 3Dimage is input is made (S910). The 3D image input to the image displaydevice 100 may be a broadcast image from a broadcast signal receivedthrough the tuner 110, an external input image from an external device,an image stored in the memory 140, or an image received from a contentprovider over a network.

The input image may be demodulated by the demodulator 120 so as to beprocessed by the controller 170, or may be directly input to thecontroller 170. As described above, the controller 170 performsdemultiplexing, decoding, or the like.

The controller 170 determines whether or not the input image is a 3Dimage signal, by referring to a 3D image flag in a stream headerindicating a 3D image, 3D image metadata, or format information of a 3Dimage.

If the input image is not a 3D image, that is, is a 2D image, step S950is immediately performed. Then, the 2D image signal processed by thecontroller 170 is converted into RGB data signals and the RGB datasignals are input to the display 180. The display 180 receives the RGBdata signals and displays a 2D image.

If the input image is a 3D image, the controller 170 processes the 3Dimage.

FIG. 10( a) shows image frames of the 3D image processed by the imageprocessing unit 420. At this time, the format of a 3D image frame 1010is a top/down format (see FIG. 5( b)).

Next, the frame rate of the 3D image is converted (S920). The FRC 450converts the frame rate of the 3D image. For example, the frame rate of60 Hz is converted to 120 Hz, 240 Hz or 480 Hz.

FIG. 10( b) shows the frame rate of the 3D image increased by the FRC450. The FRC 450 repeatedly inserts a 3D image frame 1020 so as toincrease the frame rate. At this time, the format of the 3D image is thetop/down format, without change.

Although, in FIG. 10( b), the frame rate is quadrupled, the presentinvention is not limited thereto and the frame rate may be variouslyincreased. That is, the frame rate may be doubled.

Next, the left-eye image and the right-eye image of the 3D image arealternately aligned (S930). The formatter 460 alternately aligns theleft-eye image and the right-eye image of the 3D image. That is, theformat of the 3D image is converted into the frame sequential formatshown in FIG. 5( c).

FIG. 10( c) shows the conversion of the format of the 3D image frame,the frame rate of which is converted by the FRC 450, into the framesequential format by the formatter 460.

In FIG. 10( c), a first left-eye image frame L1 (1030), a first left-eyeimage frame L1, a first right-eye image frame R1, a first right-eyeimage frame R1, a second left-eye image frame L2, and the like aresequentially arranged. That is, the same left-eye image frames areconsecutively arranged and the same right-eye image frames areconsecutively arranged.

Although not shown in the drawing, a first left-eye image frame L1, ablack frame B, a first right-eye image frame R1, a black frame B, asecond left-eye image frame L2 and the like may be sequentiallyarranged.

If the left-eye image frame and the right-eye image frame arealternately arranged by the formatter 460, the frames are input to thedisplay 180.

FIG. 11 is a diagram showing the case where the frames arranged by theformatter 460 are displayed on the liquid crystal panel 210 in thedisplay 180. FIG. 11( a) shows the actual display of the frames arrangedas shown in FIG. 10( c), and FIG. 11( b) shows liquid crystal responsecharacteristics of the liquid crystal panel 210 when the frames areactually displayed as shown in FIG. 11( a). FIG. 11( c) shows thedriving timing of the backlight lamps 252 when the conventional methodfor displaying a 3D image is used.

The horizontal axis of FIG. 11( a) denotes a time, and the vertical axisthereof denotes a vertical length of the panel.

Since the liquid crystal panel 210 has a response speed of liquidcrystal and hold type display characteristics as shown in FIG. 11( b),if the backlight lamps 252 are continuously turned on as shown in FIG.11( c), a difference between the display times of an upper side and alower side of the liquid crystal panel 210 is large and thus crosstalkis generated. In the embodiment of the present invention, a method forreducing crosstalk generated when the 3D image is displayed in the framesequential format is proposed.

Next, the left-eye image and the right-eye image of the 3D image arealternately displayed (S940).

The display 180 receives the RGB data signals for the left-eye image andthe RGB data signals for the right-eye image alternately arranged by theformatter 460, and alternately displays the left-eye image and theright-eye image.

In particular, the display 180 turns the backlight lamps 252-1 and 252-2arranged on the upper side of the liquid crystal panel 210 and thebacklight lamps 252-252-4 arranged on the lower side of the liquidcrystal panel 210 on, during a portion of a display period of theleft-eye image or the right-eye image, thereby displaying the 3D image.

Referring to FIG. 12, the backlight lamps 252 are turned on insynchronization with the left-eye image frame in a state in which theleft-eye image frame and the right-eye image frame are aligned by theformatter 460.

FIG. 12( a) shows a vertical synchronization frequency Vsync indicatinga display timing of each frame, and FIG. 12( b) shows the case where thebacklight lamps 252 are turned on in synchronization with the left-eyeimage frame and the right-eye image frame in a state in which each frameis input to the liquid crystal panel 210.

FIG. 12( b) shows the state in which the backlight lamps 252-1 and 252-2arranged on the upper side of the liquid crystal panel 210 and thebacklight lamps 252-3 and 252-4 arranged on the lower side of the liquidcrystal panel 210 are turned on during the portion of the display periodof the consecutively arranged left-eye image frames or the consecutivelyarranged right-eye image frames. By such driving, crosstalk, in whichadjacent images (the left-eye image and the right-eye image) overlapeach other when the 3D image is displayed, is reduced.

FIG. 12( b) shows the state in which the backlight lamps 252-1 and 252-2arranged on the upper side of the panel are first turned on and thebacklight lamps 252-3 and 252-4 arranged on the lower side of the panelare subsequently turned on.

Referring to the drawing, the light is transmitted from the upper sideto the central portion of the panel when the backlight lamps 252-1 and252-2 arranged on the upper side of the panel are turned on and thelight is transmitted from the lower side to the central portion of thepanel when the backlight lamps 252-3 and 252-4 arranged on the lowerside of the panel are turned on.

By differentiating the driving timings of the backlight lamps arrangedon the upper and lower sides of the liquid crystal panel 210, it ispossible to reduce power consumption when the backlight lamps aredriven. Alternatively, the backlight lamps arranged on the lower side ofthe panel may be turned on earlier than the backlight lamps arranged onthe upper side of the panel. This will be described later with referenceto FIG. 16.

FIG. 12( c) shows an on/off timing of the backlight lamps 252. In thedrawing, the backlight lamps 252 are turned on at a high level. Thebacklight lamps 252-1, 252-2, . . . , and 252-4 of FIG. 12 are used inan edge type display device, and the backlight lamps 252-1 and 252-2arranged on the upper side of the panel are turned on earlier than thebacklight lamps 252-3 and 252-4 arranged on the lower side of the panel.

FIG. 12( d) shows an operation signal timing of the shutter glasses 195.According to the operation signal timing of the shutter glasses 195,only the left-eye glass is opened when the left-eye image frames L1, L2and L3 are displayed and only the right-eye glass is opened when theright-eye image frames R1, R2 and R3 are displayed.

FIG. 13 is an enlarged diagram of the frame arrangement of FIG. 12.

Referring to the drawing, the frame arrangement of FIG. is characterizedin that the same frames are repeatedly arranged. That is, in thedrawing, the first left-eye image frame L1, the first left-eye imageframe L1, the first right-eye image frame R1, the first right-eye imageframe R1, the second left-eye image frame L2 and the like aresequentially arranged.

Accordingly, the on period Ta of the backlight lamps 252-1 and 252-2arranged on the upper side of the panel may be variously set within tworepeated left-eye image frames L1 and L1, L2 and L2, and L3 and L3 ortwo repeated right-eye image frames R1 and R1, R2 and R2, and R3 and R3.

In addition, the on period Tb of the backlight lamps 252-3 and 252-4arranged on the lower side of the panel may be variously set within tworepeated left-eye image frames L1 and L1, L2 and L2, and L3 and L3 ortwo repeated right-eye image frames R1 and R1, R2 and R2, and R3 and R3.

Accordingly, the on periods Ta and Tb of the backlight lamps 252 can bechanged and thus the brightness of the image can be adjusted.

In the drawing, the backlight lamps 252-1 and 252-2 arranged on theupper side of the panel and the backlight lamps 252-3 and 252-4 arrangedon the lower side of the panel are turned on in a last left-eye imageframe of the consecutive left-eye image frames, that is, a secondleft-eye image frame L1, L2 or L3. Accordingly, it is possible toprevent crosstalk, in which the adjacent images are displayed when the3D image is displayed.

The backlight lamps 252-1 and 252-2 arranged on the upper side of thepanel and the backlight lamps 252-3 and 252-4 arranged on the lower sideof the panel are turned on in a last right-eye image frame of theconsecutive right-eye image frames, that is, a second right-eye imageframe R1, R2 or R3. Accordingly, it is possible to prevent crosstalk inwhich the adjacent images are displayed when the 3D image is displayed.

The current level Ha of the first turned on backlight lamps 252-1 and252-2 arranged on the upper side of the panel and the current level Hbof the subsequently turned on backlight lamps 252-3 and 252-4 arrangedon the lower side of the panel may be different from each other.Preferably, the current level Hb of the subsequently turned on backlightlamps 252-3 and 252-4 arranged on the lower side of the panel may begreater than the current level Ha of the first turned on backlight lamps252-1 and 252-2 arranged on the upper side of the panel. Accordingly,the afterimage of an afterimage period when switching the image isreduced and thus crosstalk is reduced.

In FIG. 13, the on period Ta of the backlight lamps 252-1 and 252-2arranged on the upper side of the panel and the on period Tb of thebacklight lamps 252-3 and 252-4 arranged on the lower side of the panelare spaced apart from each other. Accordingly, it is possible to reduceinstantaneous current when the backlight lamps are driven and, as aresult, to reduce power consumption when the backlight lamps are driven.

FIG. 14 is similar to FIG. 13, but is different from FIG. 13 in that aportion of the on period Tc of the backlight lamps 252-1 and 252-2arranged on the upper side of the panel and a portion of the on periodTd of the backlight lamps 252-3 and 252-4 arranged on the lower side ofthe panel overlap each other. Even in this case, since the on starttimes are different, it is possible to reduce instantaneous load whenthe backlight lamps are driven and, as a result, to reduce powerconsumption when the backlight lamps are driven.

Although, in the drawing, the portion of the on period Tc of thebacklight lamps 252-1 and 252-2 arranged on the upper side of the paneland the portion of the on period Td of the backlight lamps 252-3 and252-4 arranged on the lower side of the panel overlap each other, thepresent invention is not limited thereto. When the backlight lamps 252-1and 252-2 arranged on the upper side of the panel are turned off, thebacklight lamps 252-3 and 252-4 arranged on the lower side of the panelmay be turned on. That is, the on period Tc and the on period Td mayabut on each other.

FIG. 15 is a diagram showing comparison between the current levels whena 3D image is displayed and a 2D image is displayed.

It can be seen from the drawing that current flowing in the lamp perunit frame when the 3D image is displayed is less than that when the 2Dimage is displayed. That is, a product of a time and a current levelwhen the 3D image is displayed is less than that when the 2D image isdisplayed. This is because, as shown in FIGS. 12 to 13, the backlightlamps 252-1 and 252-2 arranged on the upper side of the panel and thebacklight lamps 252-3 and 252-4 arranged on the lower side of the panelare turned on in the portion of the display period of the left-eye imageframe or the right-eye image frame.

In the embodiment of the present invention, in order to preventluminance deterioration when the 3D image is displayed, as compared withwhen the 2D image is displayed, the level H2 of instantaneous currenti_(3D) flowing in the backlight lamps 252 when the 3D image is displayedis set to be greater than the level H1 of instantaneous current i_(2D)flowing in the backlight lamps 252 when the 2D image is displayed.Accordingly, it is possible to improve luminance when the 3D image isdisplayed.

Next, FIG. 16 shows the case where the backlight lamps 252-3 and 252-4arranged on the lower side of the panel are first turned on and thebacklight lamps 252-1 and 252-2 arranged on the upper side of the panelare subsequently turned on, unlike FIG. 12.

Hereinafter, the difference between FIGS. 12 and 16 will be described.

FIG. 16( b) shows the state in which the backlight lamps 252-1 and 252-2arranged on the upper side of the liquid crystal panel 210 and thebacklight lamps 252-3 and 252-4 arranged on the lower side of the liquidcrystal panel 210 are turned on during the portion of the display periodof the consecutively arranged left-eye image frames or the consecutivelyarranged right-eye image frames. By such driving, crosstalk, in whichadjacent images (the left-eye image and the right-eye image) overlapeach other when the 3D image is displayed, is reduced.

FIG. 16( b) shows the state in which the backlight lamps 252-3 and 252-4arranged on the lower side of the panel are first turned on and thebacklight lamps 252-1 and 252-2 arranged on the upper side of the panelare subsequently turned on.

Referring to the drawing, the light is transmitted from the lower sideto the central portion of the panel when the backlight lamps 252-3 and252-4 arranged on the lower side of the panel are turned on and thelight is transmitted from the upper side to the central portion of thepanel when the backlight lamps 252-1 and 252-2 arranged on the upperside of the panel are turned on.

By differentiating the driving timings of the backlight lamps arrangedon the upper and lower sides of the liquid crystal panel 210, it ispossible to reduce power consumption when the backlight lamps aredriven.

FIG. 16( c) shows an on/off timing of the backlight lamps 252. In thedrawing, the backlight lamps 252 are turned on at a high level. Thebacklight lamps 252-1, 252-2, . . . , and 252-4 of FIG. 12 are used inan edge type display device, and the backlight lamps 252-3 and 252-4arranged on the lower side of the panel are turned on earlier than thebacklight lamps 252-1 and 252-2 arranged on the upper side of the panel.

FIG. 16( d) shows an operation signal timing of the shutter glasses 195.According to the operation signal timing of the shutter glasses 195,only the left-eye glass is opened when the left-eye image frames L1, L2and L3 are displayed and only the right-eye glass is opened when theright-eye image frames R1, R2 and R3 are displayed.

FIG. 17 is an enlarged diagram of the frame arrangement of FIG. 16.

Referring to the drawing, the frame arrangement of FIG. 17 is equal tothat of FIG. 13.

Accordingly, the on period T1 of the backlight lamps 252-3 and 252-4arranged on the lower side of the panel and the on period T2 of thebacklight lamps 252-1 and 252-2 of the panel may be variously set withintwo repeated left-eye image frames L1 and L1, L2 and L2, and L3 and L3or two repeated right-eye image frames R1 and R1, R2 and R2, and R3 andR3.

Accordingly, the on periods T1 and T2 of the backlight lamps 252 can bechanged and thus the brightness of the image can be adjusted.

In the drawing, using the boundary between the consecutive left-eyeimage frames (the boundary between L1 and L1) and the boundary betweenthe consecutive right-eye image frames (the boundary between R1 and R1)as a reference, the backlight lamps 252-3 and 252-4 arranged on thelower side of the panel are turned on before the boundary and thebacklight lamps 252-1 and 252-2 arranged on the upper side of the panelare turned on after the boundary.

That is, the backlight lamps 252-3 and 252-4 arranged on the lower sideof the panel may be turned on in the first left-eye image frame L1, L2,or L3 and the backlight lamps 252-1 and 252-2 arranged on the upper sideof the panel may be turned on in a second left-eye image frame L1, L2 orL3. Accordingly, it is possible to prevent crosstalk in which theadjacent images are displayed when the 3D image is displayed.

Alternatively, the backlight lamps 252-1 and 252-2 arranged on the upperside of the panel may be turned on in the first left-eye image frame L1,L2, or L3 and the backlight lamps 252-3 and 252-4 arranged on the lowerside of the panel may be turned on in a second left-eye image frame L1,L2 or L3. Accordingly, it is possible to prevent crosstalk in which theadjacent images are displayed when the 3D image is displayed.

The current level H3 of the first turned on backlight lamps 252-3 and252-4 arranged on the lower side of the panel and the current level H4of the subsequently turned on backlight lamps 252-1 and 252-2 arrangedon the upper side of the panel may be different from each other.Preferably, the current level of the subsequently turned on backlightlamps 252 may be greater than the current level of the first turned onbacklight lamps 252. Accordingly, the afterimage of an afterimage periodwhen switching the image is reduced and thus crosstalk is reduced.

In the drawing, since the backlight lamps 252-1 and 252-2 arranged onthe upper side of the panel are turned on later, the current level H4 ofthe backlight lamps 252-1 and 252-2 arranged on the upper side of thepanel may be greater than the current level H3 of the backlight lamps252-3 and 252-4 arranged on the lower side of the panel.

In FIG. 17, the on period T1 of the backlight lamps 252-3 and 252-4arranged on the lower side of the panel and the on period T2 of thebacklight lamps 252-1 and 252-2 arranged on the upper side of the panelare spaced apart from each other. Accordingly, it is possible to reduceinstantaneous load when the backlight lamps are driven and, as a result,to reduce power consumption when the backlight lamps are driven.

FIG. 18 is similar to FIG. 17, but is different from FIG. 17 in that aportion of the on period T3 of the backlight lamps 252-3 and 252-4arranged on the lower side of the panel and a portion of the on periodT4 of the backlight lamps 252-1 and 252-2 arranged on the upper side ofthe panel overlap each other. Even in this case, since the on starttimes are different, it is possible to reduce instantaneous load whenthe backlight lamps are driven and, as a result, to reduce powerconsumption when the backlight lamps are driven.

Although, in the drawing, the portion of the on period T3 of thebacklight lamps 252-3 and 252-4 arranged on the lower side of the paneland the portion of the on period T4 of the backlight lamps 252-1 and252-2 arranged on the upper side of the panel overlap each other, thepresent invention is not limited thereto. When the backlight lamps 252-3and 252-4 arranged on the lower side of the panel are turned off, thebacklight lamps 252-1 and 252-2 arranged on the upper side of the panelmay be turned on. That is, the on period T3 and the on period T4 may beadjacent to each other.

The current levels when the 3D image is displayed and when the 2D imageis displayed are shown in FIG. 15.

FIG. 19 is similar to FIG. 17, but is different from FIG. 17 in that thebacklight lamps 252-3 and 252-4 arranged on the lower side of the panelare first turned on and the backlight lamps 252-1 and 252-2 arranged onthe upper side of the panel are subsequently turned on, in at least alast left-eye image frame of the consecutive left-eye image frames andat least a last right-eye image frame of the consecutive right-eye imageframes.

That is, the backlight lamps 252-3 and 252-4 arranged on the lower sideof the panel and the backlight lamps 252-1 and 252-2 arranged on theupper side of the panel may be sequentially turned on in the secondleft-eye image frame L1, L2 or L3 or the second right-eye image frameR1, R2 or R3. Accordingly, it is possible to prevent crosstalk in whichthe adjacent images are displayed when the 3D image is displayed.

The on period T5 of the backlight lamps 252-3 and 252-4 arranged on thelower side of the panel and the on period T6 of the backlight lamps252-1 and 252-2 arranged on the upper side of the panel may be variouslyset within two repeated left-eye image frames L1 and L1, L2 and L2, andL3 and L3 or two repeated right-eye image frames R1 and R1, R2 and R2,and R3 and R3, unlike the drawing.

Accordingly, the on periods T5 and T6 of the backlight lamps 252 can bechanged and thus the brightness of the image can be adjusted.

In FIG. 19, the on period T5 of the backlight lamps 252-3 and 252-4arranged on the lower side of the panel and the on period T6 of thebacklight lamps 252-1 and 252-2 arranged on the upper side of the panelare spaced apart from each other. Accordingly, it is possible to reduceinstantaneous load when the backlight lamps are driven and, as a result,to reduce power consumption when the backlight lamps are driven.

The current level H5 of the first turned on backlight lamps 252-3 and252-4 arranged on the lower side of the panel and the current level H6of the subsequently turned on backlight lamps 252-1 and 252-2 arrangedon the upper side of the panel may be different from each other.Preferably, the current level H6 of the subsequently turned on backlightlamps 252-1 and 252-2 arranged on the upper side of the panel may begreater than the current level H5 of the first turned on backlight lamps252-3 and 252-4 arranged on the lower side of the panel. Accordingly,the afterimage of an afterimage period when switching the image isreduced and thus crosstalk is reduced.

FIG. 20 is similar to FIG. 19, but is different from FIG. 19 in that aportion of the on period T7 of the backlight lamps 252-3 and 252-4arranged on the lower side of the panel and a portion of the on periodT8 of the backlight lamps 252-1 and 252-2 arranged on the upper side ofthe panel overlap each other. Even in this case, since the on starttimes are different, it is possible to reduce instantaneous load whenthe backlight lamps are driven and, as a result, to reduce powerconsumption when the backlight lamps are driven.

Although, in the drawing, the portion of the on period T7 of thebacklight lamps 252-3 and 252-4 arranged on the lower side of the paneland the portion of the on period T8 of the backlight lamps 252-1 and252-2 arranged on the upper side of the panel overlap each other, thepresent invention is not limited thereto. When the backlight lamps 252-3and 252-4 arranged on the lower side of the panel are turned off, thebacklight lamps 252-1 and 252-2 arranged on the upper side of the panelmay be turned on. That is, the on period T7 and the on period T8 may beadjacent to each other.

The image display device and the method for operating the same accordingto the present invention are not limited to the configurations and themethods of the above-described embodiments, and some or all of theembodiments may be selectively combined such that the embodiments arevariously modified.

The method for operating the image display device of the presentinvention may be implemented as code that can be written to aprocessor-readable recording medium and can thus be read by a processorincluded in the image display device. The processor-readable recordingmedium may be any type of recording device in which data can be storedin a processor-readable manner. Examples of the processor-readablerecording medium include a ROM, a RAM, a CD-ROM, a magnetic tape, afloppy disc, an optical data storage, and a carrier wave (e.g., datatransmission through the internet). The processor-readable recordingmedium can be distributed over a plurality of computer systems connectedto a network so that computer-readable code is written thereto andexecuted therefrom in a decentralized manner.

Although the preferred embodiments of the present invention have beendisclosed for illustrative purposes, those skilled in the art willappreciate that various modifications, additions and substitutions arepossible, without departing from the scope and spirit of the inventionas disclosed in the accompanying claims.

1. A method for operating an image display device including a pluralityof backlight lamps arranged on upper and lower sides of a rear surfaceof a display panel, the method comprising: receiving a 3-Dimensional(3D) image; alternately aligning a left-eye image and a right-eye imageof the 3D image; and alternately displaying the aligned left- andright-eye images, wherein, in the displaying step, the backlight lampsarranged on the upper side of the panel and the backlight lamps arrangedon the lower side of the panel are turned on in a portion of a period ofthe left-eye image or the right-eye image.
 2. The method according toclaim 1, further comprising: receiving a 2-Dimensional (2D) image; anddisplaying the 2D image, wherein current flowing in the lamps per unitframe when the 3D image is displayed is less than that when the 2D imageis displayed.
 3. The method according to claim 1, further comprising:receiving a 2-Dimensional (2D) image; and displaying the 2D image,wherein the level of current flowing in the lamps when the 3D image isdisplayed is greater than that when the 2D image is displayed.
 4. Themethod according to claim 1, wherein the backlight lamps arranged on theupper side of the panel and the backlight lamps arranged on the lowerside of the panel are turned on at different times.
 5. The methodaccording to claim 1, wherein the level of current flowing in thebacklight lamps arranged on the lower side of the panel and the level ofcurrent flowing in the backlight lamps arranged on the upper side of thepanel are different.
 6. The method according to claim 1, wherein thebacklight lamps arranged on the upper side of the panel and thebacklight lamps arranged on the lower side of the panel are turned on soas to at least partially overlap each other.
 7. The method according toclaim 1, further comprising increasing a frame rate of the 3D image,wherein the aligning step and the displaying step are performed based ona left-eye image frame and a right-eye image frame.
 8. The methodaccording to claim 7, wherein, in the aligning step, the same left-eyeimage frames and the same right-eye image frames are consecutivelyarranged, and, in the displaying step, the backlight lamps arranged onthe upper side of the panel and the backlight lamps arranged on thelower side of the panel are turned on, in a portion of a periodincluding the consecutively arranged left-eye image frames or a portionof a period including the consecutively arranged right-eye image frames.9. The method according to claim 7, wherein, in the aligning step, thesame left-eye image frames and the same right-eye image frames areconsecutively arranged, and, in the displaying step, the backlight lampsarranged on the upper side of the panel and the backlight lamps arrangedon the lower side of the panel are turned on, in at least a lastleft-eye image frame of the consecutive left-eye image frames or atleast a last right-eye image frame of the consecutive right-eye imageframes.
 10. The method according to claim 7, wherein, in the aligningstep, the same left-eye image frames and the same right-eye image framesare consecutively arranged, and, in the displaying step, using aboundary between the consecutive left-eye image frames or a boundarybetween the consecutive right-eye image frames as a reference, anybacklight lamps of the backlight lamps arranged on the upper side of thepanel and the backlight lamps arranged on the lower side of the panelare turned on before the boundary and the other backlight lamps areturned on after the boundary.
 11. A method for operating an imagedisplay device including a plurality of backlight lamps arranged onupper and lower sides of a rear surface of a display panel, the methodcomprising: receiving a 2-Dimensional (2D) image; displaying the 2Dimage; receiving a 3-Dimensional (3D) image; alternately aligning aleft-eye image and a right-eye image of the 3D image; and alternatelydisplaying the aligned left- and right-eye images, wherein the level ofcurrent flowing in the lamps per unit frame when the 3D image isdisplayed is greater than that when the 2D image is displayed.
 12. Themethod according to claim 11, wherein current flowing in the lamps perunit frame when the 3D image is displayed is less than that when the 2Dimage is displayed.
 13. An image display device comprising: a formatterconfigured to alternately align a left-eye image and a right-eye imageof a 3-Dimensional (3D) image; and a display configured to alternatelydisplay the aligned left- and right-eye images, wherein the displayincludes a plurality of backlight lamps arranged on upper and lowersides of a rear surface of a display panel, and wherein the backlightlamps arranged on the upper side of the panel and the backlight lampsarranged on the lower side of the panel are turned on in a portion of aperiod of the left-eye image or the right-eye image.
 14. The imagedisplay device according to claim 13, wherein the display furtherdisplays a 2-Dimensional (2D) image, and current flowing in the lampsper unit frame when the 3D image is displayed is less than that when the2D image is displayed.
 15. The image display device according to claim13, wherein the display further displays a 2-Dimensional (2D) image, andthe level of current flowing in the lamps when the 3D image is displayedis greater than that when the 2D image is displayed.
 16. The imagedisplay device according to claim 13, wherein the level of currentflowing in the backlight lamps arranged on the lower side of the paneland the level of current flowing in the backlight lamps arranged on theupper side of the panel are different.
 17. The image display deviceaccording to claim 13, further comprising a frame rate converterconfigured to increase a frame rate of the 3D image, wherein the displaydisplays left-eye image frames and right-eye image frames aligned by theformatter.
 18. The image display device according to claim 17, whereinthe formatter consecutively arranges the same left-eye image frames andthe same right-eye image frames, and the backlight lamps arranged on theupper side of the panel and the backlight lamps arranged on the lowerside of the panel are turned on, in a portion of a period including theconsecutively arranged left-eye image frames or a portion of a periodincluding the consecutively arranged right-eye image frames.
 19. Theimage display device according to claim 17, wherein the formatterconsecutively arranges the same left-eye image frames and the sameright-eye image frames, and the backlight lamps arranged on the upperside of the panel and the backlight lamps arranged on the lower side ofthe panel are turned on, in at least a last left-eye image frame of theconsecutive left-eye image frames or at least a last right-eye imageframe of the consecutive right-eye image frames.
 20. The image displaydevice according to claim 17, wherein the formatter consecutivelyarranges the same left-eye image frames and the same right-eye imageframes, and, using a boundary between the consecutive left-eye imageframes or a boundary between the consecutive right-eye image frames as areference, any backlight lamps of the backlight lamps arranged on theupper side of the panel and the backlight lamps arranged on the lowerside of the panel are turned on before the boundary and the otherbacklight lamps are turned on after the boundary.